1. Field of the Invention
The present invention relates to a new and improved composite molded plastic article with a nut insert molded in place therein and more particularly relates to a composite molded plastic article wherein a nut insert having a threaded bore is adapted to be mounted on a pin extending into a mold cavity while a body of molded plastic material is formed around the nut insert.
2. Description of the Prior Art
Over the years, a wide variety of molded plastic articles have been provided with various types of fasteners and internally threaded inserts and the like, molded in place therein. Many different types of metal inserts having sophisticated shapes and complex outer surfaces have been developed and the following U.S. Patents have been issued relating to metal inserts, fasteners and molded plastic articles having threaded elements molded in place:
U.S. Pat. Nos. 2,359,031; 2,862,537; 3,016,578; 3,019,865, 3,085,613; 3,313,078; 3,339,609; 3,445,559; 3,485,282; 3,646,981; 3,742,995; 3,765,464; 3,809,139; 3,878,598; 3,884,006, 4,023,257; 4,051,591; 4,143,193; 4,226,550; 4,269,387; and 4,341,053.
In addition, a variety of threaded metal inserts and anchors are listed and illustrated in the 1982 addition of "Assembly Engineering Master Catalog" on pages 197-209 and in advertising pages therein illustrating "TAPTITE" products and "TORX" products made by the Camcar Division of Textron, Inc.
Many of the anchors and inserts of the prior art are relatively high in cost because of the rather exotic shapes and surfaces thereof. In addition, many inserts are difficult to utilize and are particularly hard to position and orient in a mold cavity in a molding operation. Many of the prior art anchors and inserts are subject to torsional failures and pullout failures because of overstressing or overtightening of a threaded element engaged therewith. Moreover, many of the existing metal insert systems do not provide a capability for handling an overdriven bolt or threaded member inserted therein and oftentimes overdriving a bolt causes permanent damage to the molded plastic material around the insert rendering the molded article useless. Many available inserts and anchor systems are costly to utilize because of the problem of positioning and orientating the insert within a mold in an automatic, rapid molding process.